<span><span>13−<span>6x</span></span>=<span><span><span>(<span><span>2x</span>−5</span>)</span>2</span>+3</span></span>Step 1: Simplify both sides of the equation.<span><span><span>−<span>6x</span></span>+13</span>=<span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span></span>Step 2: Subtract 4x^2-20x+28 from both sides.<span><span><span><span>−<span>6x</span></span>+13</span>−<span>(<span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span>)</span></span>=<span><span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span>−<span>(<span><span><span>4<span>x2</span></span>−<span>20x</span></span>+28</span>)</span></span></span><span><span><span><span>−<span>4<span>x2</span></span></span>+<span>14x</span></span>−15</span>=0</span>Step 3: Use quadratic formula with a=-4, b=14, c=-15.<span>x=<span><span><span>−b</span>±<span>√<span><span>b2</span>−<span><span>4a</span>c</span></span></span></span><span>2a</span></span></span><span>x=<span><span><span>−<span>(14)</span></span>±<span>√<span><span><span>(14)</span>2</span>−<span><span>4<span>(<span>−4</span>)</span></span><span>(<span>−15</span>)</span></span></span></span></span><span>2<span>(<span>−4</span>)</span></span></span></span><span>x=<span><span><span>−14</span>±<span>√<span>−44</span></span></span><span>−<span>8</span></span></span></span>
Given problem;
A = 4 π R²
To solve for R, we have to make it the subject of the expression.
Since
A = 4 π R² , follow these steps to find R;
Multiply both sides by
A x
=
x 4 π R²
= R²
Then find the square root of both sides
√R² =
R = 
The solution is 
10.99x = 3.99x + 280
7x = 280
x = 40
They must sell 40 T-shirts to break even
Answer:
Option C.The decrease in the value of the motorcycle, which is 9%
Step-by-step explanation:
we have a exponential function of the form

where
a is the initial value
b represents growth or decay factor
If b >1 then it is an exponential growth
if 0<b<1 then it is an exponential decay
In this problem
a=$19,000
b=0.91 -----> it is exponential decay factor
Find the rate of decrease r
b=(1-r)
substitute
0.91=1-r
r=1-0.91=0.09
Convert to percentage
0.09*100=9%
therefore
0.91 represent the decrease in the value of the motorcycle, which is 9%